title: Thermoreversible physical gels of poly(dimethylsiloxane) without cross-links or functionalization.
abstract: The preparation of gels of poly(dimethylsiloxane) (PDMS) reported in the literature so far involves catalysts and chemical cross-links (chemical gels) or functionalization with organogelators. We report that thermoreversible physical gels of PDMS, without cross-links or functionalization, can be made with propylamine or hexylamine as a solvent. The gels consist of spherical domains as small as 20 nm. We show that these spherical domains are part of a network. Differential scanning calorimetry (DSC), optical microscopy, and rheology show that the gel is thermoreversible. With the DSC experiments, we have devised a procedure to achieve thermoreversibility with very similar gel-sol transition endotherms in the first and second heating cycles.
authors.affiliation: Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada.
authors.forename: Elianne
authors.initials: E
authors.lastname: Dahan
authors.forename: Pudupadi R
authors.initials: PR
authors.lastname: Sundararajan
mesh_terms: D000588:Amines / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D004129:Dimethylpolysiloxanes / Q000138:chemical synthesis / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D010316:Particle Size; D013499:Surface Properties; D013696:Temperature
chemical_list: D000588:Amines; D004129:Dimethylpolysiloxanes; D005782:Gels; C013830:baysilon